Almost everything you do today uses a code. Everytime you log onto an internet service like Twitter or Facebook and send your password...everytime you log into internet banking...all of that information is protected using encryption code. - PBS NOVA - Rise of the Hackers
50 Minute Video from PBS Nova provided below.
Prime numbers. Remember that from grade Four math class. If you don't, follow this link. - Prime Number on Wiki
In fourth grader lingo, it's a number that is divisible by itsel...